Mentions:
The interaction of two variables, pH and tryptone, is shown in Fig. 1A, the 3D response surface plot indicates that interaction of these components moderately affected the production of l‐DOPA. The higher and lower levels of these components did not affect the l‐DOPA yield drastically, but mid‐levels provide a maximum yield. The acidic and alkaline pH results in lower l‐DOPA yields might be because of inhibition of tyrosinase activity and cell viability. Also at alkaline pH, less l‐DOPA yield resulted due to the conversion of l‐DOPA into further metabolites such as dopaquinone and melanin (Ali and Haq, 2006). The pH 3.5 and 5.4 has been reported for bioconversion of l‐DOPA by using biomass of Aspergillus oryzae and Yarrowia lipolytica respectively (Ali and Haq, 2006; Ali et al., 2007). The shape of the 3D response surface curve of the interaction between pH and l‐tyrosine depicted in Fig. 1B shows that l‐DOPA production was drastically affected by a slight change in the levels of these two factors. The higher and lower concentrations of both factors resulted in lesser l‐DOPA yield.

Mentions:
The interaction of two variables, pH and tryptone, is shown in Fig. 1A, the 3D response surface plot indicates that interaction of these components moderately affected the production of l‐DOPA. The higher and lower levels of these components did not affect the l‐DOPA yield drastically, but mid‐levels provide a maximum yield. The acidic and alkaline pH results in lower l‐DOPA yields might be because of inhibition of tyrosinase activity and cell viability. Also at alkaline pH, less l‐DOPA yield resulted due to the conversion of l‐DOPA into further metabolites such as dopaquinone and melanin (Ali and Haq, 2006). The pH 3.5 and 5.4 has been reported for bioconversion of l‐DOPA by using biomass of Aspergillus oryzae and Yarrowia lipolytica respectively (Ali and Haq, 2006; Ali et al., 2007). The shape of the 3D response surface curve of the interaction between pH and l‐tyrosine depicted in Fig. 1B shows that l‐DOPA production was drastically affected by a slight change in the levels of these two factors. The higher and lower concentrations of both factors resulted in lesser l‐DOPA yield.

Bottom Line:
The optimization of medium using RSM resulted in a 8.355-fold increase in the yield of L-DOPA.L-DOPA production was confirmed by HPTLC, HPLC and GC-MS analysis.Thus, Brevundimonas sp.